Variable attenuator



Filed Oct. 15, 1952 INVENTOR. /kA/wr Owens-avril Jan. l2, 1954 QN l NM.Q BM. .WN N N NM. @www DN l QN @uw NN a. www NN m 7 7 /f 7 /r ,NN u f.0N NN ,WN .WN W7 www `7 J NN WN NN NN NN m. NM. QM NM.

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Patented Jan. 12, 1954 2,65*@183 VARIABLE .A1-mueres Frank J.0cnascl1ekDallas, Tex.; assignorV to ,Hollins` Radio `(lolurlpany, Cedari Rapids;v Iow'a',

e qrpereiieiwf Application lOctotb'ear 1952, Serial No. 314,804

Thisrinvention relates to-a variable attenuator material 29. A resistor3i! has one side conf- Whereinthe-impedance'mayibevaried-toprovdenectedtothe inner conductor 28. A lead-31' is a change in coupling.`connected to the other sideV of resistor `Sliffarid jltis? oftentimesdesirable to lattenuate .a high, to a second'capacitor disc 3 l.

ultra-high, or very high Afri-o uency signal to ai 5 A'fourth resistor32 has one end connected toA fraction'of its-value; "At other times itdesir.- the disc 3| by a lead 38 and its opposite endA able to match,mpedancesso that the ,most attached to the memberf23 by solder material33;:

eilcient utilization of power ma?! bev Obtaind: vAtapered threadedportion? 34' is attach'edto, =It`isanobiectof this invention, therefore,Lto the cylinder it and a tapered threadedcollar: DIOI@ 'a--VlablellmlatOr and COlllllrlg .der 10 35-is received' thereon'so as to clampthe mem`` vicevvhereintheamountzof coupling and imned: ber `23 to themember 34. The internal threads.v ance maybevariedatwill. of the collar35 aretapered .opposite fto .thetap'er, feature -of this invention isfound in. the of the threads oimember `Bil.4 When the collarv provision`for afgenerally .cylindrical ,cal/{ty'QS 351s loosened Ythe member .23may be rotated or onatorwhichhas mounted/atopposterends input 15 slidrelative to cylinder lll by suitablelevers `36. lines-:connected tocapacitor .plates :by a .pair G` When the collar .35:is tightened,vthemember leadsfsoastoiform ,an 4inchlctive coupling. 23 is rigidlyheld and cannot .be rotated.A

Further -features, objects and Jadriftrlilfties will FigureiZillustrates schematically .the appaandclaimsfwhenreadin `view of`the,f-lfftivlfles z 20 thrcapacitor fplates 2i! and n:ilare1c,anacitively n-which; i couplefipto .eachother andinductances L1and La Figure risasectioual viewloifthefvatebe 'etareinductively.coupledtoeach Qthtr- The i11- nuator of this. invention, .and` 4dutance L1 is the loop comprisinathe leadsll. Egurez isa .schematic`vievv illustrating the and,38;and3platec31. ,The indugtange-11aj5-Agheelectrical equivalents of the circuit. 25 loopeformedphy:the leads39 and34,9 and the,

Figure ALillus'trates a `hollovv conducting .Cyl' plate-2.0'-

inder l0 whhi-hasrmounttd in 011e end thereof Theacoupliue 4between thecapacitive Plates an internal conducting plug ll- It iS fastened loa-nd.lpmav be varied `by,Ilflovrl.themerigir tothemember lo by set' screwsi2 or other tudi-nally 4relativetoeach other, ,frhiskmaynbeuoiingiiieans. .aecomolishe,dlov` loosening the .sleeve mand member H`and' a portion lli enlarged and 36. Thisallpws .coarse ,adjustmentof theco threaded. A coaxial cable connector 45N 1S plingbetyveen theinputand,ontputsioles .Minor threadedly 'received/Q in the portion I 4 andytermladjustments, mayfhe ,mdefbr 1 meting l Wel-mem, nanas in an outerconductor I5 and an inner ber 23 relative to the member" I' so that 'theconductor Il. The inner and outer conductors 3v coupling loopscomprising L1 and L2 rotate relare insulated from each other byinsulation maative to each other so that the coupling is varied terialI8. The outer conductor i6 is electrically from a maximum to a minimumValue. This connected t0 the Conducting DOTOH H but the allows neadjustments to be made :at these inner conductor I7 is insulatedtherefrom. frequengiea A resistor I9 has one side electrically connectedLlo other advantages that are obtainable with to one end of the innerconductor l1 and its this structure are; opposite end is connected to alead 39 which 1s 1, can be used over a large frequency range, connectedto a rst capacitive plate 20. A sechigh frequency, very high frequencyand ultra ond resistor 2| is connected to a lead it which highfrequency. is connected to the plate 2li. The other side 45 2. Very lowstanding wave ratio.

of resistor 2| is connected to the plate I by 3. Provides sameattenuation over Wide fresolder material. quency ranges.

The opposite end of the cylinder l0 re'lves 4. Will withstand severeconditions of shock therein a second plug 23 of conducting material andVibration which is formed with a central Opening 24 and 50 5.Longitudinal movement provides coarse conwhich has a threaded portion 25in which a trol, and rotational movement provides fine second coaxialconnector 26 is received. control.

The outer conductor 21 of the connector 2t is 6. Can be used as animpedance transformer connected to the member 23, whereas the inner aswell as an attenuator by changing the values conductor 28 is insulatedfrom it by insulation 55 of resistance in either end of attenuator.

goodies 7. Can be inserted anywhere in transmission line.

8. Has no tuned elements, therefore does not require tuning and is verystable with respect to frequency temperature and humidity changes.

9. Provides a common conductor.

10. Can be used in a balanced circuit by suitable changes in circuitarrangement.

It is seen that this invention provides a variable attenuator orimpedance transformer which may be very accurately adjusted.

Although this invention has been described with respect to a particularembodiment thereof, it is not to be so limited as changes andmodications may be made therein which are within the full intended scopeof the invention, as defined by the appended claims.

I claim:

1. A variable impedance and coupling device comprising, a hollowconducting cylindrical member, aflrst internal conducting plug receivedwithin one end of said cylinder, said first plug formed with an axialopening, a first coaxial connector connected to said first plug, a rstresistor mounted within the axial opening of said first plug andconnected to the center conductor of said coaxial cable connector, `afirst capacitive plate attached to the opposite side of said firstresistor, a second resistor with one end attached to said rst plug andthe opposite end connected to said rst capacitive plate, a second plugrotatably and slidably supported in said cylinder and formed with anaxial opening, a third resistor mounted within the axial opening of saidsecond plug, `a second capacitive plate attached to one side of thethird resistor, a second coaxial connector connected to said secondplug, and a fourth resistor connected between said second plug and saidsecond capacitive plate.

2. A variable coupling and impedance matching device comprising, ahollow cylindrical member, a first plug formed with a centrallongitudinal opening mounted in one end of said cylindrical member, afirst resistor mounted in said longitudinal opening, a coaxial connectorconnected to said first plug and its center conductor connected to oneside of said resistor, a first capacitive disc connected to the otherside of the first resistor, a second resistor connected between saidfirst capacitive disc and said first plug, a second plug slidably androtatably received in said cylindrical member, a second coaxialconnector connected to said second plug, said second plug formed with alongitudinal opening. a third resistor mounted in said longi tudinalopening with one lead connected to the center conductor of said coaxialconnector, a second capacitive plate attached to the other lead of saidthird resistor, a fourth resistor connected between the second plug andthe second capacitive plate, and a lever attached to said second plugfor rotating and moving it longitudinally relative to said cylindricalmember.

3. A variable attentuator and coupling device comprising, a. hollowconducting cylindrical member, a pair of plugs mounted in opposite endsof said cylindrical member, said plugs formed with longitudinal openingstherethrough, a pair of coaxial connectors mounted, respectively, tosaid plugs, a rst resistor formed with a pair of relatively rigid leadsextending from opposite ends thereof, one of the leads of said firstresistor connected to a first capacitive disc, said first resistormounted in the longitudinal opening of the first plug and the oppositelead of said first Vresistor connected to the center conductor of thefirst coaxial connector, a second resistor formed with a pair ofrelatively rigid leads with one of the leads connected to the first plugand the other lead connected to said first capacitive disc, a thirdresistor mounted in the longitudinal opening of the second plug andhaving a pair of relatively rigid leads, a second capacitive plateconnected to one of said leads of the third resistor, the other of saidleads of the third resistor attached to the center conductor of thesecond coaxial connector, a fourth resistor with relatively rigid leads,one of its leads connected to the second plug and the other leadconnected to the second capacitive plate. and Yfastening means forloosening and tightening the second plug relative to said cylindricalmember.

4. Apparatus according to claim 3 wherein said fastening means comprisesa tapered threaded portion on one end of said cylindrical member, and aninternally threaded tapered collar receivable on said rst taperedportion.

FRANK J. OCNASCHEK.

References cited in the fue of thispatent UNITED STATES PATENTS NumberName Date 1,888,278 MacDonald Nov. 22, 1932 2,422,601 Tashjian June 17,1947 2,494,722 Rosen Jan.'17, 1950 2,514,544 Hansen V July 11', 19502,561,184 Dehn July 17, 1951V

